I wish to center an object vertically on it's own page. Is there a simple way of doing this?

Perhaps someone could point me to a css statement!

Own 'screen' or own file?
When it comes to Images, the problem is screens come in 3 sizes: to short, too long, just right . If you have a 800x600 screen and a 800x600 image (which is slight too big), then you try and display on a smaller screen?

Have not tried:
set the (Image) height: 80%; margin-top: 5%; margin-bottom: 5%